US20070297118A1

US20070297118A1 - Electrostatic Chuck Device

Info

Publication number: US20070297118A1
Application number: US11/666,950
Authority: US
Inventors: Yoshinori Fujii
Original assignee: Individual
Current assignee: Ulvac Inc
Priority date: 2004-11-04
Filing date: 2005-10-27
Publication date: 2007-12-27
Also published as: CN101278385B; WO2006049085A1; JP5323317B2; CN101278385A; KR20080107473A; KR20070072571A; TWI390698B; US7821767B2; TW200618249A; JPWO2006049085A1; US20110013338A1

Abstract

The object of this invention is to provide that an electrostatic chuck device which can properly and promptly diselectrify a substrate to be processed.

In an electrostatic chuck device (11) attracting a substrate (W) to be processed on the surface of a susceptor (12) electrically, a diselectrifying circuit is provided which includes diselectrifying electrode means (16) facing the surface of the susceptor (12), a diselectrifying potential (19), and a diselectrifying resistance (17) connected between the diselectrifying electrode means (16) and the diselectrifying potential (19). The resistance value of the diselectrifying resistance (178) is established such that it is lower than that of an insulating layer (13) of the surface of the susceptor (12 and the diselectrifying resistance (17) can hold the potential of the substrate (W) during an electrostatic chuck operation, and such that the diselectrifying reistance 17) can dissipate the potential of the substrate (W) into the ground potential (19) when the electrostatic chuck is canceled. This structure can appropriately and promptly diselectrify the substrate (W).

Description

TECHNICAL FIELD

The present invention relates to an electrostatic chuck device which is used for a semiconductor manufacturing process, for example.

BACKGROUND OF THE TECHNIQUE

Conventionally, when a substrate to be processed such as, for example, a semiconductor wafer is processed in a vacuum, an electrostatic chuck device is used to fix the substrate in a vacuum chamber. This kind of electrostatic chuck device has an insulating layer (a dielectric layer) on a susceptor for supporting the substrate. Static electricity occurs by applying voltage between the susceptor and the substrate through the insulating layer, thereby the substrate is attracted by the susceptor.
There are mainly a monopole type and a bipolar type in electrostatic chuck mechanism. FIG. 10 shows diagrammatically a configuration of a prior art electrostatic chuck device 1 having the electrostatic chuck mechanism of the bipolar type.
Referring to FIG. 10, an insulating layer 3 on which semiconductor substrate W is put is formed on the surface of a susceptor 2. Plural electrostatic chuck electrodes 4A, 4A, 4B and 4B are placed in the inside of the susceptor 2 to be facing the back surface of the semiconductor substrate W which is put on the insulating layer 3.
At first, the semiconductor substrate W is put on the surface of the susceptor 2. Next, the chuck electrodes 4A are connected to a predetermined positive potential source 5A, and the chuck electrodes 4B are connected to a predetermined negative potential source 5B. As the result, the back surface of the semiconductor substrate W is electrified with polarity shown in FIG. 10. Static electricity occurs between the substrate W and the chuck electrodes 4A and 4B through the insulating layer 3, thereby the semiconductor substrate W is attracted and held to the surface of the susceptor 2.
When the semiconductor substrate W is detached from the susceptor 2, the chuck electrodes 4A and 4B are connected to the ground potential as shown in FIG. 11, respectively, thereby these chuck electrodes 4A and 4B are diselectrified. Thus, the static electricity between the semiconductor substrate W and the chuck electrodes 4A and 4B disappears. Afterwards, the back surface of the semiconductor substrate W is pushed up by lifter pins (illustration abbreviation), and the semiconductor substrate W is transported to the next process through a transportation robot (illustration abbreviation).
The chuck electrodes 4A and 4B are generally made of low resistance material (for example carbon, aluminum, copper). Thus, after having interrupted voltage power supply to these chuck electrodes 4A and 4B, if the electrodes chuck 4A and 4B are connected to ground potential, the diselectrification of the chuck electrodes 4A and 4B are completed instantly. In contrast, because the insulating layer 3 made of high resistance material intervenes between the semiconductor substrate W and the chuck electrodes 4A and 4B, diselectrification of the substrate W cannot be performed positively. Therefore, depending on resistance value of the insulating layer 3, much time is needed for diselectrification of the substrate W.
Thus, after having connected the chuck electrodes 4A and 4B to ground potential, there is the case that the electrostatic attraction exists between the back surface of the semiconductor substrate W and the insulating layer 3. In this case, there is fear that the substrate W is damaged by the upthrust of the lifter pins or that a transportation error of the substrate W is occurred.
Other method for diselectrification of the substrate is to constitute the lifter pins with metal and to connect them to ground potential. As the result, the substrate is diselectrified by contacting with the lifter pins. However, depending on the quantity of the electric charge remaining in the substrate W, there is the case that an arc discharge occurs between the substrate and the lifter pins. In this case, the discharge signs are formed on the substrate back surface. Furthermore, there is the case that the elements on the substrate are damaged.
As a conventional substrate diselectrification method, there are diselectrification by applying reverse voltage, diselectrification by using plasma and diselectrification by heating up the insulating layer to solve such problems.
The diselectrification by applying reverse voltage is a method which provides a reverse electric potential to the chuck electrodes 4A and 4B, and which dissipates the electric charge from the semiconductor substrate W. The method of the diselectrification by using a plasma generates a plasma in a process chamber after having connected the chuck electrodes 4A and 4B to ground potential, and dissipates the substrate W through the plasma, as shown typically in FIG. 12 (see patent document 1). The method of the diselectrification by heating up the insulating layer 3 is a method which decreases the specific resistance of the insulating layer 3 by raising its temperature and which promote diselectrification of the semiconductor substrate W.
Patent Document 1: JP2004-14868

DISCLOSURE OF INVENTION

Problem to be Solved by the Invention

Although the diselectrification by applying a reverse voltage can accelerate the diselectrification of the dielectric layer (insulating layer 3), there is a problem which can not immediately dissipate the potential of the substrate.
The diselectrification by using a plasma has many problems. That is to say, this method can not be applied to the process that cannot use a plasma. Diselectrification effect of a central part of the back surface of the substrate is little. Because the electrode (ground) for diselectrification always face a process chamber, film formation material is deposited to the electrode, and the electrode is deteriorated by sputtering. As a result, frequent reproduction maintenance of the electrode comes to be necessary.
Even more particularly, in the diselectrification by the heating up of the insulating layer 3, there is the fear that element deterioration is caused depending on kinds of the substrate W because the substrate temperature also rises with rise in temperature operation of the insulating layer 3. Also, it takes much time to rise temperature of the insulating layer 3.
This invention has been made in consideration of the above problems. It is an object of the present invention to provide an electrostatic chuck device which can properly and immediately diselectrify a substrate regardless of the kinds of the processes.

Means for Solving Problem

To solve the above object, an electrostatic chuck device of the present invention is characterized by comprising a diselectrifying circuit which includes:
diselectrifying electrode means facing the surface of a susceptor,
diselectrifying potential and,
diselectrifying resistance connected between the diselectrifying electrode means and the diselectrifying potential.
In the diselectrifying circuit of the above construction, diselectrifying electrode means always contacts with back surface of the substrate which is put on the susceptor. The diselectrifying electrode means is connected to the diselectrifying potential (for example, ground potential) through the diselectrifying resistance. Resistance value of the diselectrifying resistance is established such that it is lower than that of an insulating layer of the surface of the susceptor, the diselectrifying resistance can hold the potential of the substrate during an electrostatic chuck operation, and such that the diselectrifying resistance can dissipate the potential of the substrate into the diselectrifying potential when the electrostatic chuck is canceled. This resistance value can appropriately established depending on applied voltage in the electrostatic chuck or process condition.
According to the present invention, the diselectrifying electrode means is always contacting with the substrate to be processed, and appropriate diselectrifying resistance intervenes between the diselectrifying electrode means and the diselectrifying potential. Accordingly, diselectrification of the substrate can be processed properly without causing overdischarge such as the arc, at the time of diselectrification of the substrate. The substrate is diselectrified as soon as chuck electrode is connected to ground potential. Further, diselectrification process can be performed immediately because diselectrification efficiency is high.
The position that the diselectrifying electrode means is formed, is not limited in particular, but it is preferred that the diselectrifying electrodes means is formed on the periphery of the susceptor or the surface of the susceptor through the space between plural chuck electrodes placed in the inside of the susceptor. Also, the diselectrifying electrode means can be comprised with a conductor film which formed in film forming process onto the susceptor surface, or can be comprised with a metallic projection. The formation of the diselectrifying electrode means can be chosen in scope being able to obtain a desired electrostatic chuck function.
The diselectrifying potential may be ground potential, and may be a predetermined power supply potential which can supply the potential different from the potential of the substrate.
The diselectrifying resistance represents resistance component between the diselectrifying electrode means and the diselectrifying potential. The diselectrifying resistance is comprised with a resistance element such as a resistor placed between the diselectrifying electrode means and the diselectrifying potential, but it may be comprised with resistance component of wiring material. Also, the resistance element may be comprised with a variable resistance as well as a fixed resistance.
In a case that the diselectrifying resistance is comprised with a variable resistance, the diselectrifying resistance is established at its higher resistance side in order to restrain the leakage of the electric potential of the substrate during an electrostatic chuck operation, and is established at its lower resistance side in order to dissipate the potential of the substrate immediately when the electrostatic chuck is canceled. In the diselectrifying circuit regarding the present invention, similar effect can be obtained by including a switch means which connects/cuts-off electrically between the diselectrifying electrode means and the diselectrifying potential. That is, the leakage of the substrate potential during an electrostatic chuck operation can be prevented by switch-off of the switch means, and diselectrification of the substrate can be immediately performed by switch-on of the switch means.

EFFECT OF THE INVENTION

As above described, according to an electrostatic chuck device of the present invention, it can be properly and immediately diselectrify a substrate to be processed. Thus, at detachment, the substrate can be prevented from its transportation error or its damage by the influence of the residual charge, and through-put and productivity can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an electrostatic chuck device 11 according to a first embodiment of the present invention.
FIG. 2 is enlarged partial views of examples of top surface 16A of diselectrifying electrodes 16.
FIG. 3 is a view of one example of diselectrifying electrodes 16 arranged between chuck electrodes 14A and 14B.
FIG. 4 is a view of another example of diselectrifying electrodes 16 arranged between chuck electrodes 14A and 14B.
FIG. 5 is a schematic view of an electrostatic chuck device 21 according to a second embodiment of the present invention.
FIG. 6 is a schematic view of an electrostatic chuck device 31 according to a third embodiment of the present invention.
FIG. 7 is a schematic view of an electrostatic chuck device 41 according to a fourth embodiment of the present invention.
FIG. 8 is a schematic view of an electrostatic chuck device 51 according to a fifth embodiment of the present invention.
FIG. 9 is a schematic view of an electrostatic chuck device 61 according to a sixth embodiment of the present invention.
FIG. 10 is a schematic view of a prior art electrostatic chuck device.
FIG. 11 is a view for explanation of one substrate diselectrification method in a prior art electrostatic chuck device.
FIG. 12 is a view for explanation of another substrate diselectrification method in a prior art electrostatic chuck device.

EXPLANATIONS OF LETTERS OR NUMERALS

11,21,31,41,51,61 electrostatic chuck device
12 susceptor
13 insulating layer
14,14A,14B chuck electrode
15,15A,15B electric potential source for chuck
16,52 diselectrifying electrode
17,27 diselectrifying resistance
19,49 diselectrifying potential
38 switch
53 biasing member
62 lifter pin (diselectrifying electrode)
63 lift unit

BEST EMBODIMENT OF THE INVENTION

Each embodiment of the present invention will be described with reference to the drawings. Note that, the present invention is not limited to following embodiments, and various kinds of modifications are possible based on the technical idea of the present invention.

First Embodiment

FIG. 1 is a schematic view showing a configuration of an electrostatic chuck device 11 according to a first embodiment of the present invention. The electrostatic chuck device 11 of this embodiment comprises mainly, a susceptor 12 which supports a semiconductor substrate W; an insulating layer (dielectric layer) 13 formed on the surface of the susceptor 12; plural chuck electrodes 14A and 14B which are arranged at the inside of the susceptor 12 and which are facing the semiconductor substrate W through insulating layer 13; and diselectrifying electrode 16 which is faced to the surface of the susceptor 12 and which can contact with back surface of the semiconductor substrate W.
The susceptor 12 is made of ceramic or other insulating material and is installed in a process chamber of a vacuum chamber which is not illustrated. The insulating layer 13 is made of PBN (pyrolytic boron nitride), AlN (aluminum nitride) in this embodiment, but of course it can be made of other insulating materials except these. The insulating layer 13 may be formed on the whole of the surface of the susceptor 12 not only a part of the surface of susceptor 13.
The chuck electrodes 14A and 14B are made of low resistive material such as carbon, aluminum, copper and so forth. The chuck electrodes 14A are connected to a positive potential source 15A, and the chuck electrodes 14B are connected to a negative potential source 15B. Switches 18A and 18B are arranged between the chuck electrodes 14A, 14B and the potential sources 15A, 15B. These switches 18A and 18B are respectively replaced to ground potential side when the semiconductor substrate W is diselectrified.
The diselectrifying electrode 16 is formed on the periphery of the susceptor 12. The tip of the electrode 16 is placed on the surface of the susceptor 12 so that it can contact with the back surface of the semiconductor substrate W. The position where the diselectrifying electrode 16 is attached is good at all area on the periphery of the susceptor 12. And the diselectrifying electrode 16 may be arranged at the plural positions of equality angular intervals or inequality angular intervals along the periphery of the susceptor 12.
As shown in FIG. 2A, the tip 16A of the diselectrifying electrode 16 covers the predetermined area on the top surface of the periphery of the susceptor 12. Accordingly, contact area with the back surface of semiconductor substrate W can be enlarged. Further, as shown in FIG. 2B and 2C, the electrode tip 16A can properly contact with the back surface of the substrate W not only when the size (diameter) of the semiconductor substrate W is larger than the surface size of the susceptor 12 but also when it is small.
The diselectrifying electrode 16 may be arranged not only on the periphery of the susceptor 12 but also for example through spaces between the chuck electrodes 14A and 14B, as shown in FIG. 3 and FIG. 4. In these cases, the diselectrifying electrodes 16 are formed so as to face the surface of the insulating layer 13 through the spaces between the chuck electrodes 14A and 14B placed at the inside of the susceptor 12. Also, the formation of the tip of the diselectrifying electrode 16 may be spotted, shown in FIG. 3, and linear, showing FIG. 4. The chuck electrodes 14A and 14B are pectinate shape in FIG. 3 and are fan shape in FIG. 4.
The material of the diselectrifying electrode 16 is not limited in particular, but low resistive material such as a metal is preferable. Also, as a configuration of the diselectrifying electrode 16, conductor film formed on the periphery (and a part of surface thereof) of susceptor 12 in film process can be applied. The diselectrifying electrode 16 may be a bulk, too. In this embodiment, the diselectrifying electrode 16 is formed by a copper film.
The diselectrifying electrode 16 is connected to ground potential 19 which corresponds to the diselectrifying potential in this invention, through a diselectrifying resistance 17. The diselectrifying resistance 17 has the resistance value that can restrain a leakage of a potential of the semiconductor substrate W during an electrostatic chuck operation, and that can dissipate the potential of the semiconductor substrate W into the ground potential when the electrostatic chuck is canceled.
The resistance value of this diselectrifying resistance 17 is appropriately determined, depending on chuck potential (potential supplied to potential sources 15A and 15B), distance between the substrate W and chuck electrodes 14A and 14B, a square measure and arrangement number of the chuck electrodes 14A and 14B, process condition of the semiconductor substrate W. In any case it is necessary that the resistance value of the diselectrifying resistance is lower than the resistance value of insulating layer 13. In one instance, when chuck potential is 3,600V, the resistance value of the diselectrifying resistance 17 is established larger than 1 kΩ, preferably is 0.5 MΩ.
A diselectrifying circuit of this invention consists of the diselectrifying electrode 16, the diselectrifying resistance 17 and the ground potential 19.
The electrostatic chuck device 11 of this embodiment is constructed as above. When the electrostatic chuck device 11 attracts and holds the semiconductor substrate W which has been put on the surface of the susceptor 12, the chuck electrodes 14A are connected to the positive potential source 15A, and the chuck electrodes 14B are connected to the negative potential source 15B, and the predetermined positive potential and negative potential are supplied to the chuck electrodes 14A and 14B, respectively. Therefore, each area of the semiconductor substrate W back surface opposed to the chuck electrode 14A and 14B is polarized in each negative charge and positive charge by electrostatic induction through the insulating layer 13, and is electrified. As the result, an electrostatic attraction force occurs between the semiconductor substrate W and the susceptor 12, and the semiconductor substrate W is held on the susceptor 12.
Then, there is fear that the potential of the substrate W leaks out into the ground potential 19 side because the diselectrifying electrode 16 contacts with the back surface of the semiconductor substrate W, but the leakage can be controlled by adjusting the diselectrifying resistance 17 adequately as above mentioned.
Also, the negative charge is supplied from the ground potential 19 to the semiconductor substrate W through the diselectrifying resistance 17 because the diselectrifying electrode 16 contacts with the back surface of the semiconductor substrate W. It contributes to increase in attraction force of the semiconductor substrate W. Such an effect becomes particularly remarkable when the chuck electrode consists of a single electrode and when the semiconductor substrate is electrified by negative charge.
The semiconductor substrate W is detached from the susceptor 12 after a predetermined process (for example, a film forming process or an etching process) for the semiconductor substrate W has been completed. Then, it needs to release the attraction power between the substrate W and the susceptor 12 by diselectrifying the substrate W.
In this embodiment, the switch 18A and 18B are respectively changed over from potential source side into the ground potential side, thereby the chuck electrodes 14A and 14B are diselectrified. Afterwards, the semiconductor substrate W is diselectrified through the diselectrifying electrode 16, mainly. That is to say, diselectrification of semiconductor substrate W is performed immediately just to change the switch 18A, 18B. Afterwards, the semiconductor substrate W is lifted by a lifter pins (illustration abbreviation) towards the upper side, and is transported to the next process by a predetermined transportation robot (illustration abbreviation).
According to this embodiment, the diselectrification of the semiconductor substrate W can be performed properly, so that it can be prevented from transportation error or damage when the substrate W is detached. Also, electrostatic chuck device 11 can be produced with low cost because the configuration of the diselectrifying circuit can be simplified very much. Further, the detachment of semiconductor substrate W can be operated without decreasing through-put of the process or productivity because it does not need a special processing operation for diselectrification.
Further still, the diselectrifying electrode 16 always contacts with the back surface of the semiconductor substrate W, and the diselectrifying resistance 17 intervenes between the diselectrifying electrode 16 and the ground potential 19. Hence, the generation of overdischarge such as the arc can be suppressed when the semiconductor substrate W is diselectrified. Accordingly, the semiconductor substrate W can be protected.

Second Embodiment

FIG. 5 is a schematic view of an electrostatic chuck device 21 according to a second embodiment of the present invention. Parts that correspond to those in the above first embodiment, are denoted by the same reference numerals, and the detailed description of which will be omitted.
In this embodiment, the electrostatic chuck device 21 has the diselectrifying electrodes 16 facing the surface of the susceptor 12. The diselectrifying electrodes 16 are arranged not only on the periphery of the susceptor 12 but also at interior portions of the surface of the susceptor 12. The diselectrifying electrodes 16 arranged at the interior portions of the surface of the susceptor 12 intervene between plural chuck electrodes 14A and 14B placed at inside of the susceptor 12. And the tips of the diselectrifying electrodes 16 are exposed in point shape or linear shape toward the surface of the insulating layer 13 between the electrodes 14A and 14B as shown in FIG. 3 and FIG. 4.
Therefore, when the semiconductor substrate W is diselectrified, the diselectrification effect that is approximately uniform in whole area of substrate W can be obtained. The diselectrification efficiency can be improved and the diselectrification time can be shortened.
Also in the electrostatic chuck device of this embodiment, a diselectrifying resistance 27 which constitutes the diselectrifying circuit consists of a variable resistance. This diselectrifying resistance 27 is established toward its higher resistance side in order to restrain the leakage of the potential of the semiconductor substrate W during an electrostatic chuck operation, and is established toward its lower resistance side in order to immediately dissipate the substrate potential when the electrostatic chuck is canceled.
Thus, an attraction power of the semiconductor substrate W and efficiency of the diselectrification can be raised more, so that the diselectrification time can be largely shortened. Also, because the diselectrifying resistance can be appropriately adjusted depending on the conditions of the process for the semiconductor substrate W, a preferable chuck potential which is different every process can be supplied to the semiconductor substrate W.

Third Embodiment

FIG. 6 is a schematic view of an electrostatic chuck device 31 according to a third embodiment of the present invention. Parts that correspond to those in the above first embodiment, are denoted by the same reference numerals, and the detailed description of which will be omitted.
In this embodiment, the electrostatic chuck device 31 has a switch 38 arranged between the diselectrifying resistance 17 and the ground potential 19, thereby a diselectrifying circuit for the semiconductor substrate W is comprised. This switch 38 corresponds to “the switching means” of the present invention. The switch 38 may be constituted by a mechanical switch member or an electronic circuit such as transistor.
According to this embodiment, because the switch 38 which electrically connects/cuts-off between the diselectrifying electrode 16 and the diselectrifying potential (ground potential) 19 is comprised, the leakage of the substrate potential can be prevented by switch-off of the switch 38 during an electrostatic chuck operation, and the diselectrification of the substrate W can be immediately performed by switch-on of the switch 38. Accordingly, the resistance of the diselectrifying resistance 17 can be lower. And the possibility which has adverse effect on a process such as RF plasma treatment that substrate electrification potential is important can be cleared. Also, generation of the -arc between the diselectrifying electrode 16 and the semiconductor substrate W can be restrained by installation of the diselectrifying resistance 17.

Fourth Embodiment

FIG. 7 is a schematic view of an electrostatic chuck device 41 according to a fourth embodiment of the present invention. Parts that correspond to those in the above first embodiment, are denoted by the same reference numerals, and the detailed description of which will be omitted.
In electrostatic chuck device 41 of this embodiment, a positive electric potential source 15 is connected through a switch 18 to the chuck electrodes 14 which are placed at inside of the susceptor 12. Particularly, an example that a diselectrifying circuit has been comprised by a positive potential source 49 supplying a potential different from the potential of the semiconductor substrate W is shown.
According to this embodiment, because the diselectrification of the semiconductor substrate W can be performed positively by the positive potential source 49, the diselectrification efficiency of the semiconductor substrate W can be improved, and the effect that is similar to the first embodiment can be obtained.
Potential level of the positive potential source 49 for diselectrification can be determined depending on the electrification potential of the semiconductor substrate W. Also, the most suitable diselectrification potential depending on the kind of the semiconductor substrate W can be given if this positive potential source 49 is comprised in variable potential source. Of course, the potential source 49 for the diselectrification is comprised with negative potential source when the potential source supplying to the chuck electrodes 14 is comprised with the negative potential source.

Fifth Embodiment

FIG. 8 is a schematic view of an electrostatic chuck device 51 according to a fifth embodiment of the present invention. Parts that correspond to those in the above first embodiment, are denoted by the same reference numerals, and the detailed description of which will be omitted.
In the electrostatic chuck device 51 of this embodiment, the back surface of the semiconductor substrate W which is put on the surface of the susceptor 12 is contacted with diselectrifying electrodes 52 which are accommodated in through-holes 54 formed at the plural positions respectively on the surface of the susceptor 12. These diselectrifying electrodes 52 are connected to connecting terminals 55 attached to the lower limit side of through-holes 54 through coiled spring-shaped biasing members 53, respectively. The biasing members 53 correspond to “biasing means” of the present invention. The diselectrifying electrodes 52, the biasing members 53 and the connecting terminals 55 consist of a conductive material such as metal respectively.
In this embodiment, similarly to the third embodiment, a diselectrifying circuit for the semiconductor substrate W is comprised in which the switch 38 is placed between the diselectrifying resistance 17 and the ground potential 19. The diselectrifying resistance 17 is connected to the connecting terminals 55 connecting with diselectrifying electrodes 52.
In the electrostatic chuck device 51 of this embodiment, the diselectrifying electrode 52 always contacts with the back surface of semiconductor substrate W which is put on the surface of the susceptor 12, by biasing force of the biasing members 53. The biasing force of the biasing members 53 is established lower enough than the self-weight of the semiconductor substrate W. Thus, the chuck power for the semiconductor substrate W by the chuck electrodes 14A and 14B is not affected.
In the electrostatic chuck device of this embodiment, when electrostatic chuck for the semiconductor substrate W is canceled, the switches 18A and 18B are changed over to the ground potential side, thereby the chuck electrodes 14A and 14B are diselectrified. Afterwards, the switch 38 for the diselectrification of the substrate is closed. By closing the switch 38 for diselectrification, the potential of the semiconductor substrate W is dissipated into the ground potential 19 through the diselectrifying electrodes 52, the biasing members 53, the connecting terminals 55, the diselectrifying resistance 17 and the switch 38. Therefore, the semiconductor substrate W is diselectrified.
Accordingly, the effect similar to the respective above-mentioned embodiments can be obtained by the electrostatic chuck device 51 of this embodiment. Particularly according to this embodiment, because the diselectrifying electrodes 52 always contact with the back surface of the semiconductor substrate W with predetermined contact pressure, contact resistance with semiconductor substrate W decreases, and the diselectrification of the semiconductor substrate W can be performed immediately. Also, when camber or waviness occur in semiconductor substrate W, an appropriate contact condition between the diselectrifying electrodes 52 and the semiconductor substrate W can be secured. Also, generation of the arc between the diselectrifying electrodes 52 and the semiconductor substrate W can be restrained by the diselectrifying resistance 17.

Sixth Embodiment

FIG. 9 is a schematic view of an electrostatic chuck device 61 according to a sixth embodiment of the present invention. Parts that correspond to those in the above first embodiment, are denoted by the same reference numerals, and the detailed description of which will be omitted.
In the electrostatic chuck device 61 of this embodiment, a lift mechanism which lifts the semiconductor substrate W to be put on the susceptor 12 is attached at the lower position of the susceptor 12. This lift mechanism comprises a lifter pin 62 and a lift unit 63 which lifts the lifter pin 62 in the vertical direction to the surface of the susceptor 12.
The lifter pin 62 is comprised as a diselectrifying electrode concerning the present invention. The lifter pin 62 is accommodated to a through-hole 64 formed in susceptor 12. Tip of the lifter pin 62 contacts with the back surface of the semiconductor substrate W during an electrostatic chuck operation as shown in figure. One lifter pin 62 is shown in the figure, but of course plural lifter pins 62 may be arranged at plural positions.
The lifter pin 62 is made of a conductive material such as a metal, and is fixed to a driving member 63 a of the lift unit 63. The lift unit 63 is constituted by a driving source with a high repeat accuracy of the locations such as a electromotive cylinder or a compressed air cylinder. The driving member 63 a is moved in vertical direction by the lift unit 63 as shown in a figure arrow. The lifter pin 62 is moved between the position where the tip of the lifter pin 62 projects from the surface of the susceptor 12 and the position where the lifter pin 62 is accommodated in the through-hole 64, by means of the vertical movement of the driving member 63a. The driving member 63 a is attached at the susceptor 12 through a circular insulating member 66 and bellows 65.
The driving member 63 a of the lift unit 63 is made of a conductive material such as metal. The lifter pin 62 is connected to the diselectrifying resistance 17 through this driving member 63 a. This diselectrifying resistance 17 is connected to ground potential through the switch 38.
In the electrostatic chuck device 61 of this embodiment, it is controlled so that the tip of the lifter pin 62 contacts with the back surface of the semiconductor substrate W by the lift unit 63 during an electrostatic chuck operation. Then, by control of lifting torque of the lift unit 63, it may make a lifter pin 62 contact with the back surface of the semiconductor substrate W in the range of the pressure that does not affect electrostatic chuck effect.
The effect similar to statement above can be obtained by the electrostatic chuck device 61 of this embodiment, and the diselectrification of the semiconductor substrate W can be immediately performed when the electrostatic chuck is canceled. Further, it can be prevented that arc occurs between the back surface of the semiconductor substrate W and the tip of the lifter pin 62 by excess current.
Note that, in each embodiments, semiconductor substrate W was nominated for example as a substrate to be processed, but, for example, as well as this, the present invention can apply a glass substrate or the conductor substrate to, too.

Claims

1-11. (canceled)

12. An electrostatic chuck device for electrostatically attracting a substrate to be processed to a surface of a susceptor, the device comprising:

diselectrifying electrode means facing said susceptor surface;

a diselectrifying potential source; and

a diselectrifying vairable resistance connected between said diselectrifying electrode means and said diselectrifying potential source;

said diselectrifying electrode means arranged and positioned whereby it will always contact a back surface of a substrate placed on said susceptor surface.

13. An electrostatic chuck device according to claim 12, in which said diselectrifying electrode means is formed on a periphery of said susceptor.

14. An electrostatic chuck device according to claim 12, in which said diselectrifying electrode means is formed through a space provided between plural chuck electrodes placed in the inside of said susceptor.

15. An electrostatic chuck device according to claim 12, in which the potential of said diselectrifying potential source is ground.

16. An electrostatic chuck device according to claim 12, in which the potential of said diselectrifying potential source is a predetermined power supply potential.

17. An electrostatic chuck device according to claim 12, including a switch means which connects/cuts-off electrically between said diselectrifying electrode means and said diselectrifying potential source.

18. An electrostatic chuck device according to claim 12, including biasing means attached to said diselectrifying means and biasing said diselectrifying electrode means toward said surface of said susceptor.

19. An electrostatic chuck device according to claim 12, in which said diselectrifying electrode means is arranged at plural positions relative to said surface of said susceptor.

20. An electrostatic chuck device according to claim 12, in which said diselectrifying electrode means is connected to a unit which can move said diselectrifying electrode means in a direction toward the surface of said susceptor.